The present invention relates to systems and components for paying-off an elongate material, and more particularly, to devices for transferring the pay-off of the elongate material from one rotating package to another.
The capacity of a roll of material used in a manufacturing operation may be insufficient for a production run, which can lead to undesirable results, for example, either a residual amount of material is left on the roll or the material can be consumed before the production run has ended. In the first case, the partial roll requires extra inventory space, or it may be discarded as scrap. When the material on a roll is less than is required for a full production run, the roll may be required to be changed out, or two rolls may be spliced together one or more times during the production run. Both the roll changing and splicing operations undesirably contribute to manufacturing costs and delay.
Pay-off devices are often used to unwind or xe2x80x9cpay-offxe2x80x9d the material on pads, for example, armor tape used in optical cable manufacturing operations. Respective pay-off devices may hold more than one pad of material, but can require an interruption in the operation for splicing. In order to reduce the frequency of splices, and reduce the likelihood of operator error, large bulk volumes of wound tape referred to as xe2x80x9cpackagesxe2x80x9d may be used. A package is made up of many layers of tape wound along the length of a tubular core and may include side flanges.
A variable accumulator/dancer is typically positioned between the pay-off device and the production line to compensate for any substantial differences between the tape pay-off feed rate and production line tape demand rates, typically measured in feet per minute. A accumulator/dancer typically has opposing sets of rollers that the tape is fed through. One of the sets of rollers can move relative to the other set to increase or decrease the length of tape accumulated within the accumulator/dancer to account for the tape rate difference. The accumulator/dancer senses the tape feed rate from the pay-off device and, through a feedback control loop, controls the rotational speed of the pay-off to tape rate difference to a minimum.
One aspect of the present invention encompasses an unwinding apparatus. The unwinding apparatus includes a pay-off device having a motor, a brake and a shaft rotatable about a longitudinal axis, wherein the motor and the brake control the rotational speed of the shaft. The unwinding apparatus includes a transition device having a first package having a first core. The first core has an axis of rotation, the first core being mounted on a rotatable shaft having a length of a first elongate material having a tail end. The unwinding device includes a second package having a second core, the second core having an axis of rotation generally coaxially aligned with the first core axis of rotation, the second core having a length of a second elongate material having a head end. The transition device supports at least a portion of one of the elongate materials, the first elongate material being contiguous with the second elongate material by means of a connection therebetween, so that pay-off between the first and second packages occurs essentially without interruption.
Another aspect of the invention includes a package having a length of elongate material wound about a core of the package. The package includes a primary core portion and an extended core portion contiguous with the primary core portion, the extended core portion extending beyond a radial side of the package. In addition, the length of elongate material defines a body portion and a tail portion, the body portion being wound about the primary core portion, the tail portion being contiguous to the body portion and wound about the extended core portion, the length of the body portion of the elongated material being greater than the length of the tail portion of the elongate material.